Separable attachment plug



March 11, 1924.

N. w. NUTT SEFARABLE ATTACHMENT PLUG Filed Sept. 1, 1921 I N VENTOR.

:4 TTORNE Y.

Patented Mar. 11, 1924.

PATENT OFFICE.

NORIvIAN W. NUTT, F TRENTON, NEW JERSEY.

SEPARAIBLE ATTACHMENT PLUG.

Application filed September 1, 1921.

To all whom it may concern:

Be it known that 1, Norman W. Near, a citizen of the United States, residing at Trenton, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in Separable Attachment Plugs, of which the following is a specification.

This invention relates to improvements in separable attachment plugs and has for its principal object to provide for certain refined features of construction and arrangement of the parts thereof, whereby to provide for more efficient electrical connection between the current conducting contact between the same, when the separable parts of the attachment plugs are joined together.

With the foregoing and other objects in View, the invention resides in the certain novel and useful construction and arrange ment of parts, as will be hereinafter more fully described, set forth in the appended claims, and illustrated in the accompanying drawings, in which Figure 1 is a vertical section taken on the line 11 of Figure 2, and showing a preferred form of the separable attachment plug with the cap portion thereof in position for insertion into cooperative engagement with the base portion of the same,

Figure 2 is a bottom plan view of the base portion of the plug and showing the manner of attaching the contact members and screw shell in position thereon,

Figure 3 is a section through the base portion of the plug, the same being taken on the line 38 of Figure 2,

Figure 4 is a sectional view corresponding to that of Figure 1, but showing the separable parts of the plug joined together into operative relation one with respect to the other,

Figure 5 is a front and side elevation of the contact member to be electrically connected to the screw shell of the base portion of the plug,

Serial No. 497,518.

Figure 6 is a front and side elevation of the center contact member of the base portion of the plug.

Referring to the drawing, wherein similar characters of reference designate corresponding parts throughout the several views thereof, the numeral 10 indicates the cap portion of the attachment plug, and the numeral 11 the base portion thereof, both portions 10 and 11 being formed of an insulating material or composition, such as porcelain or the like.

The top portion 10 is provided with a centrally disposed opening 12 through which the usual conductors or leads (not shown) are inserted for attachment to the usual contact screws 13 passed downwardly through recesses 14 formed in the cap portion to either side of the central opening 12. the recesses 14 being, after the screws 13 are positioned therein, filled with a sealing material, whereby the latter are held against movement or displacement from; operative position. The lower face of the cap 10 preferably concaved or otherwise suitably recessed as at 15 to admit of the conductors being twisted or knotted, after insertion through the opening 12, whereby all strain is taken fromthe ends thereof connecting the contact screws 13. Secured to the lower ends of the screws 13 are the clutch engaging contact members or fingers 16, the connected ends of these fingers 16 being angularly bent for engagement with the screws 13, and areal-ranged to dispose the free end portions thereof in projecting or depending spaced parallel relation one with respect to the other.

The base portion 11 of the plug is formed at its upper end 17. as of a diameter corresponding to that of the cap portion 10, and is cxteriorly reduced in diameter inwardly from its lower end 18 to receive thereon a usual form of threaded metal shell 19, adapted for engagement with the correspondingly threaded shell of a lamp bracket or the like (not shown). The base portion isforlned to provide a pair of channel ways 21 and 22 extending longitudinally thereof and spaced diametrically apart one from the other in a manner to be aligned with the contact fingers 16 of the cap portion 10, which are adapted to be inserted within the same. The base or plug portion 11 is further formed to provide a central cylindrical portion 23, which is projected outwardly of the reduced end portion thereof, and the free end of this portion is formed substantantially frustro-conical as at 24, so that its extreme outer end is of substantially equal diameter to that of the head of a contact bolt or screw 25, which is passed inwardly of a bore formed centrally and longitudinally in the portion 23, the reduced end portion 24, of the latter, being counter sunk to seat the head 26 of the bolt or screw 25 and dispose the same flush in the plane of the end face of the portion 23, the inner end of the bolt or screw 25 being secured within the recess 27 by means of a nut 28.

Extending inwardly of the channel ways 21 and 22 of the device as shown in Figures 1 to 6, inclusive, and from the reduced end portion of the base or plug 11, are a pair of resilient or spring contact members or jaws, the one extending into the channel way 21 being formed as is shown in Figure 6, of a single piece of sheet metal and having the outer end portion 29 thereof angularly bent and apertured, as at 30, for engagement under the head 26 of the central contact bolt or screw 25, and a leg portion 31 which is split inwardly of the free end of the same to provide a centrally disposed tongue portion 32, which tongue portion 32 is angularly bent, as at 33, in oil-set relation with respect to the opposite side portions of the leg portion 31, and at a point immediately adjacent to its point of connection with the latter, and is similarly bent as at 3 1-, but in a reverse direction, at a point inwardly from its free end, the tongue portion 32 being disposed so that the angularly bent portion 34; thereof normally projects inwardly of and between the opposite split portions of the leg portion 31, the extreme end portions 35 and 36' of the split leg portions and the tongue portion 32 being disposed angularly one from the other whereby to permit the ready insertion between the same of a complemental contact finger 16 of the cap portion. Outwardly of the channel way 22 in the base or plug 1.1, is a second resilient or spring contact member or jaw of sheet metal, and the same is formed at its outer end with an angularly disposed portion 37, which is substantially semi-circular in plan, so that the opposite ends of the same are secured under the heads of a pair of bolts or screws 38 and 39, which are passed through longitudinally disposed openings formed in the base or plug 11 diametrically thereof and to either side of the central screw 25. hen fastened in proper position, the portion 37 is clamped, under the action of the bolts 38 and 39, in electrical contact with an inturned portion 10 formed with the screw shell 20. The leg portion ll of this contact member or jaw, is formed identically with respect to the leg portion 31 of the other of the members or jaws, and

the parts or" the same are correspondingly designated with the reference characters 32, 33, 34, 35 and 36. The inner ends of the bolts or screws 33 and 39 are projected into recesses l2 and 43, formed inwardly of the larger end of the base or plug 11 and are each provided with securing nuts 14: and 45, respectively, and when the same, together with the central bolt 25 and its securing nut 23, are secured in proper position, the recesses, 27, 42 and as are to be filled with a suitable sealing compound whereby to prevent the accidental loosening up of the several nuts 28, 1 1 and 4:5.

The extremely important and valuable features of the invention primarily resides in the provision of the resilient or spring contact members or jaws within the channel ways 21 and 22, of the base portion 11 of the plug, whereby a very eilicient and etifective electrical contact is established between the same and the contact lingers 16 of the cap portion 10 of the plug; also in the interlocking of the angularly bent portions 34;, 3a with the apertures or recesses 59 formed in the contact fingers 16 of the cap member 10 to prevent the accidental separation of the parts of the attachment plug; further, in the arrangement of the tongue portions of the base contact members or jaws acting to retain the latter parallel to the opposite walls of the channel ways 21 and 22, whereby to efiect a rubbing contact between the faces of the same opposed to those of the cap contact fingers 16; and in the angularly bent or flared end portions of the base contact members for guiding the cap contact fingers 16 into proper contacting relation with respect to the base contact members or jaws. It is to be noted also that the resiliency of the base contact members or jaws assures of the positive contact of the same with the cap contact fingers 16 irrespective of the fact as to whether or not the latter are straight or have become slightly irregular in shape during the constant use of the same. By making the contact members or jaws from single pieces of sheet metal, the same can be cheaply manufactured and of a sutficient rigidity in construction as to be durable and eflicient in use.

It is well understood that, while the preferred embodiments of the devices have been described and illustrated herein in specific terms and details of construction and arrangement, various changes in and modifications of the same may be resorted to without departing from the spirit of the invention, or the scope of the claim appended hereto.

Having thus fully described the invention, what is claimed, is

A contact member for separable attachment plugs, comprising a strip of sheet metal having a tongue portion displaced from the longitudinal center of the free end portion thereof to provide a resilient contact j aw, said tongue being off-set from said strip at a point adjacent its point of connection therewith and further angularly bent inwardly from its free end to provide a projecting portion adapted for engagement with an aperture formed in a complemental contact member adapted to be engaged in the said jaw, the free ends of said strip and tongue portions being angularly and oppositely bent or flared for guiding the said coinplemental contact member into cooperative engagement with the said jaw.

In testimony whereof, I affix my signature hereto.

NORMAN W. NUTT. 

